I am interested in Graflex Xl and considering buying one with a Heligon 95mm lens. But before finally purchasing one, I've still got a few questions. Hope you guys/senior members could help me sort it out.

1. Is it possible to use a dioptrical eyepiece to the rangefinder coupled viewfinder?
2. I know the frame line is for 80mm and 100mm lens. Is it any bit inconvenience when using a 95mm lens on a Graflex XL?
3. I've heard that original Graflex film black could perhaps not provide a very flat film for the shooting? Is it true?

BTW, I also got some interest on the Graflex Combat 70(KE-4) 70mm camera, which is a medium format rangefinder too. Its base length is outrageous. Despite the inconvenience using and developing 15ft 70mm film, does it provide automatic pallarax collection as the Graflex XL?
And also the question of using a dioptrical eyepiece to the viewfinder?